A battery such as a lithium-ion battery is widely used in different electronic devices. The battery usually includes a shell, a core within the shell and a cover plate assembly configured to seal an opening in the shell. The cover plate assembly includes: a cover plate, a negative connection sheet and an insulation sheet. During the process of riveting the cover plate, the negative connection sheet and the insulation sheet, it is easy for the negative connection sheet to rotate with respect to the cover plate due to an impact force, such that the negative connection sheet is deflected and it is easy for a short circuit to occur. In addition, an end of the negative connection sheet far away from a connection position between the negative connection sheet and the cover plate is easy to deform, such that the end of the negative connection sheet is cocked up.